Construction of a chamber for cooling hot gases

ABSTRACT

A construction of a chamber for cooling hot gases such as fuel gases or combustion gases includes means for introducing the hot gases into the chamber in a whirling flow and into contact with a coolant which is preferably in solid form and is located within the chamber. The gases contact the coolant and cause the coolant to slowly dissolve while the gases are cooled down. The coolant is advantageously made of a L-shaped cross-sectional configuration and it includes a wall which surrounds the outlet to the chamber, and which forms, with the chamber wall, an over flow weir for the outflow of the gases after they have been cooled within the chamber. The coolant itself advantageously includes means such as longitudinally extending grooves for forming rotatable eddies on the whirling gas flow which intensify the heat exchange between the relatively cooled boundary layer and the hotter rotating layers of the whirling gas flow located further inside radially. In another embodiment the coolant chamber advantageously includes a front wall or closed wall located opposite the outlet which carries the coolant lining in a solid form.

United States Patent Munding et ai.

[451 June6,1972

- [54] CONSTRUCTION OF A CHAMBER FOR COOLING HOT GASES Germany Messerschmitt-Bolkow-Blohm Gesellschaft mit beschrankter Haftung, Ottobrunn near Munich, Germany [22] Filed: Mar. 3, 1970 [21] Appl.No.: 16,006

[73] Assignee:

[30] Foreign Application Priority Data Mar. 5, 1969 Germany ..P 19 ll Q78.2 June 19, 1969 Germany.. ..P 19 30 990.1

[52] US. Cl ..62/5,l65/l, 165/133 12/ l 965 Bramekamp ..62/120 3,534,555

10/1970 Webb Primary Examiner-William J. Wye Attorney-McGlew and Toren ABSTRACT A construction of a chamber for cooling hot gases such as fuel gases or combustion gases includes means for introducing the hot gases into the chamber in a whirling flow and into contact with a coolant which is preferably in solid form and is located within the chamber. The gases contact the coolant and cause the coolant to slowly dissolve while the gases are cooled down. The coolant is advantageously made of a L-shaped cross-sectional configuration and it includes a wall which surrounds the outlet to the chamber, and which forms, with the chamber wall, an over flow weir for the outflow of the gases after they have been cooled within the chamber. The coolant itself advantageously includes means such as longitudinally extending grooves for forming rotatable eddies on the whirling gas flow which intensify the heat exchange between the relatively cooled boundary layer and the hotter rotating layers of the whirling gas flow located further inside radially. In another embodimentthe coolant chamber advantageously includes a front wall or closed wall located opposite the outlet which car ries the coolant lining in a solid form.

14 Claims, 4 Drawing Figures PATENTEDJUM 51972 3.6671241 SHEET 10F 2 III FIQ 1 1 1 10 II 2 INVENTORS German Munding Willi Zeh By V/ fl KM ATTORNEYS PATENTEDJUH 6 1972 3.667, 241

SHEET 2 BF 2 INVENTORS German Mupding Wllll Zeh By fl fiu/XW ATTORNEYS CONSTRUCTION OF A CHAMBER FOR COOLING HOT GASES SUMMARY OF THE INVENTION This invention relates in general to a cooling chamber construction and in particular, to a new and useful cooling chamber construction for treating hot gases particularly combustion gases or fuel gases and particularly for cooling such gases with a coolant preferably in a solid form.

Gases which are produced in combustion chambers with the combustion of fuel with oxygen and particularly gases produced in rocket combustion chambers which employ an oxygen carrier and a fuel usually have a very high temperature so that they are unsuited, without cooling, for various fields of applications such as for driving gas turbines or for use as pressure gases for the transport of fuel components for rocket engines. In combustion chambers such as those which use an airoxygen combustion, as much air is admixed to the hot flame core, which is produced in the front part of the fire box, as is needed to attain the drop in temperature required for a succeeding heat sensitive machine. such as a turbine which will be highly stressed from a strength standpoint. Fuel gases produced, often in a vacuum, by rocket firing processes cannot be supplied with air to reduce their temperature for technological reasons. In such cases it is known to employ a so-called cooling chamber after the combustion chamber for lowering the temperature of the gases. Such a chamber is usually filled with a solid chemical coolant of endothermic characteristics such as ammonium oxalade having a plurality of longitudinal holes extending therethrough. The very hot fuel gases flow through the holes and thereby dissolve the coolant while the gases themselves become cooled. The coolant then mixes in a gaseous form with the fuel gas, for example as described in the issue of Space Aeronautics of October 1961 on pages 75 and 76. Since it takes a certain time, and hence a certain length of coolant, to dissolve the coolant itself and also to cool the fuel gases, the cooling chamber must have an appropriate length. In rockets and space craft in which the structural dimensions play an essential role the structural length required for the known cooling chamber is not always available or is extremely difficult to provide.

An object of the present invention is to provide a spacially small specifically short cooling chamber having a great cooling capacity. In order to solve this problem in accordance with the invention the cooling chamber is designed in a form of a longitudinally relatively short chamber having a tangential hot gas inflow and it is lined with a coolant. A feature of the construction is the tangential introduction of the hot gases so that they are whirled around the inner circumference of the chamber and hence travel a very long distance. In addition, the construction permits a considerable gas flow distance for generating eddy currents. This is true because the distance covered by the hot gases inside the thin chamber is practically the product of velocity times the dwell for any given diameter of spin chamber.

In one embodiment of the invention, the cooling chamber is lined with a solid coolant of substantially L-shaped cross sectional configuration and one leg of the coolant is located to extend radially inwardly into the coolant chamber adjacent the outlet thereof. By this measure the coolant forms an overflow weir which ensures a sufficiently long dwell of the fuel gases within the spin chamber to provide a satisfactory cooling action. This also enhances the erosion action on the coolant and also provides for a greater heat exchange between the various revolving layers of the helically progressive flow of hot gases within the cooling chamber. In accordance with the feature of the invention a plurality of grooves preferably those which extend in a longitudinal direction and are parallel to each other are provided around the interior wall of the coolant and they produce rotatable eddies which intensify the heat exchange between the boundary layer of the gases which already contact the coolant and with the outer higher temperature gases which are continuously being tangentially directed into the cooling chamber.

As is known, the drop in velocity of the rotating medium (fluidum) which occurs with increasing radius of curvature in a rotating flow is accompanied by a unidirected increase in pressure. Consequently, there prevails in the central area of the operational cooling chamber, according to the invention, a lower pressure than in the radially outer areas. This flow induced pressure difference and frictional influences bring about secondary axially oriented return flows in the form of a toroid which collide with the inside of the front face of the cooling chamber at a location opposite the cooling chamber outlet.

In another embodiment of the invention the cooling chamber is lined with a solid coolant at the interior or closed end adjacent the wall which is opposite to the outlet and the secondary return currents in the form of a toroid which are generated are utilized for the ablation of the solid coolant. The gases which reach the coolant lining at the front face wall of the chamber along with the secondary return currents in the form of a toroid which are generated in the central area of the chamber move radially outwardly past the coolant lining and dissolve much of the coolant as they move. The gases thus are cooled down very rapidly and as they reach the radially external chamber area, they are thoroughly mixed with the rotating gas layers of the primary whirling gas flow which intersect their flow path in that area so that they too experience a lowering of their temperature. The cooled rotating gas layers then move radially outwardly, because of their greater specific gravity, under the influence of centrifugal force and they displace the still uncooled relatively hot gases in a radially inward direction where these hot gases become included in the secondary return flows in the form of a toroid and are brought by them into contact with the coolant lining of the front face wall of the chamber. Tests have proven that the implementation form of the cooling chamber according to the invention and operating in this manner furnishes excellent cooling results.

Since the secondary return flows in the form of a toroid which are developed in the cooling chamber according to the invention contribute to the implementation form described above the major portion of the ablation work, it is often sufficient to cover the central portion of the front face wall of the chamber with a coolant only at a location directly opposite the chamber outlet and only in the area which corresponds to the projection area of the chamber outlet.

Accordingly, it is an object of the invention to provide an improved chamber for cooling hot gases and in particularly for cooling fuel gases or combustion gases and using a solid coolant which includes means for introducing the hot gases in a tangential whirling direction over the surface of the coolant which is arranged within the chamber.

A further object of the invention is to provide a cooling chamber construction which includes an interior having a solid coolant lining advantageously formed with a plurality of longitudinally extending grooves for the production of rotatable eddies and also preferably including a radially inwardly extending leg portion adjacent the outlet of the cooling chamber forming a weir for controlling the outflow of the gases as they are cooled and wherein the chamber includes means for tangentially directing the high temperature gases to be cooled into the chamber in a whirling flow proceeding from the closed end and progressing in a helical spiral around the interior walls toward the outlet.

A further object of the invention is to provide a cooling chamber which includes means for tangentially introducing high temperature gases into the chamber adjacent a closed end in a whirling axially progressing flow for movement toward an outlet end and which advantageously includes a solid coolant arranged at the closed end and preferably covering an area corresponding to a centrally arranged outlet at the opposite end.

A further object of the invention is to provide a cooling chamber for high temperature gases to facilitate their use in devices which require gases at a lower temperature and which is simple in design, rugged in construction, and economical to manufacture.

A further object of the invention is to provide a method of treating high temperature gases in order to cool them which comprises tangentially directing them into a cooling chamber to flow in a whirling stream which proceeds in an axial direction and brings about secondary axially oriented return flows in the form of toroid, and moving them into contact with a solid coolant as they are so flowing while generating rotatable eddies on the whirling gas stream to facilitate erosion of the coolant and an intermixing of the gases, and permitting the cooled gases to flow outwardly through a centrally located outlet which is bounded by a wall which functions as a weir to permit an overflow of the cooled gases through the outlet.

A further object of the invention is to provide a method of treating high temperature gases in order to cool them which comprises tangentially directing them into a cooling chamber to flow in a whirling stream which proceeds in an axial direction and brings about secondary axially oriented return flows in the form of a toroid, and moving said secondary axially oriented return flows into contact with a solid coolant, and permitting the cooled gases to flow outwardly through a centrally located outlet which is bounded by a wall which functions as a weir to permit an overflow of the gases through the outlet.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAMNGS In the drawings FIG. 1 is a longitudinal sectional view of a cooling chamber constructed in accordance with the invention;

FIG. 2 is a section taken on the line II-II of FIG. 1;

FIG. 3 is a section taken on the line IIIIII of FIG. 1; and

FIG. 4 is a view similar to FIG. 1 of another embodiment of the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in particular the invention embodied therein in FIG. 1, comprises a cooling device or cooling chamber vessel generally designated 10 which is made of a compressed longitudinal form with a closed end 10a and having a central opening 10b at a discharge or opposite end 100. The device 10 defines a spin chamber 1 which is provided with a coolant lining 2 of generally L-shaped cross section and of a material such as a solid coolant. The lining 2 includes a leg portion or annular flange 2a which lies adjacent the opened end 100 and forms an overflow weir which forms a retarded action on the longitudinal progression of the hot gas flow until the gas is sufficiently cooled to move inwardly and flow outwardly through the central opening 10b.

In accordance with one feature of the invention hot gases are tangentially introduced through an inlet 5 and they move in the direction of the arrow 4 in a whirling axially progressing flow around the interior wall of the device 10. In accordance with a further feature of the invention the interior wall of the coolant is advantageously provided with a plurality of longitudinally extending grooves 3 which cause the hot gases 4 to form rotatable eddies, 6 which intensify the heat exchange between the relatively cooled boundary layer and the hotter rotating layers located further inside radially.

In the embodiment of the invention indicated in FIG. 4, there is provided a cooling device 10 having an inner or front closed wall 100' and an opposite wall 100 having a central opening forming an outlet 10b. The device 10' includes a cylindrical wall 7 and a conical front wall 8. The hot gases are tangentially admitted through openings 5 for flow in a direction of the arrow 4' and in tangential whirling directions which progress axially toward the outlet 10b. In this embodiment, the wall 8 is provided with a block of solid coolant 12 in an area which corresponds to the projection of the opening 10b but located at the front or closed end. The solid coolant is of a material such as ammonium oxalade.

In this arrangement secondary, axially oriented return flows in the form of a toroid 14 which are brought about by flow induced pressure difference and frictional influences in the spin chamber 1' are utilized for the ablation of the coolant lining 12 and ablate it intensively.

What is claimed is:

l. A cooling chamber construction comprising wall means defining an axially short whirl chamber of relatively great diameter, means for introducing high temperature gases tangentially into said chamber for flow adjacent the interior walls thereof, means defining an outlet at a spaced location from the means for introducing the high temperature gases, and a solid coolant block located within said chamber adjacent the walls thereof in a position to be contacted by the hot gases as they move around the walls and axially toward the outlet.

2. A cooling chamber construction according to claim I, wherein said solid coolant block is of L-shaped cross section and includes a leg portion forming a radially inwardly extending annular flange adjacent the outlet and providing a weir for regulating the flow of the gases.

3. A cooling chamber construction, according to claim 1, wherein said coolant block includes a plurality of longitudinally extending grooves therein providing means for forming a plurality of eddies of gases adjacent the wall of said coolant.

4. A cooling chamber construction, according to claim 1, wherein said solid coolant is located adjacent the closed end of said chamber and opposite to the outlet.

5. A cooling chamber construction, according to claim 1, wherein said solid coolant block is arranged in the closed end of said chamber opposite to said outlet and being of a size substantially equal to the size of said outlet.

6. A cooling device comprising a tubular member having a closed end and an opposite end with an opening forming a discharge, means for introducing high temperature gases at at least one location adjacent the closed end for whirling tangential flow around the interior of said tubular member and for axial movement in a helical flow toward said outlet, and a solid coolant block located within said tubular member adjacent the walls thereof in a position to be contacted by said gases.

7. A cooling device, according to claim 6, wherein said solid coolant is of L-shaped cross section and includes a leg portion forming a radially inwardly extending annular flange adjacent said outlet and providing a weir for regulating the flow of the gases.

8. A cooling device, according to claim 6, wherein said coolant includes a plurality of longitudinally extending grooves therein providing means for forming a plurality of eddies of gases adjacent the wall of said coolant.

9. A cooling device, according to claim 6, wherein said solid coolant is located adjacent the closed end of said tubular member and opposite to the outlet.

10. A cooling device, according to claim 6, wherein said solid coolant is arranged in the closed end of said tubular member opposite to said outlet and being of a size substantially equal to the size of said outlet.

1 l. A method of treating high temperature gases in order to permit them to be used for devices requiring gases at a lower temperature comprising tangentially directing the gases into a whirling chamber and over the surface of a solid coolant so as to cause the gases to move against the coolant and to dissolve the coolant and to be cooled thereby.

12. A method, according to claim 1 1, including superimposing rotatable eddies on the primary whirling gas flow.

13. A method, according to claim 11, including utilizing secondary axially oriented return flows in the form of a toroid which are brought about by flow induced pressure difference and frictional influences in said whirling chamber for the ablation of said coolant.

14. A' method, according to claim 11, including damrning the flow of gases as they are moved in an axial direction to cause them to build up centrally and permitting the gases to move through a central outlet as the damming action causes them to build up. 5 

1. A cooling chamber construction comprising wall means defining an axially short whirl chamber of relatively great diameter, means for introducing high temperature gases tangentially into said chamber for flow adjacent the interior walls thereof, means defining an outlet at a spaced location from the means for introducing the high temperature gases, and a solid coolant block located within said chamber adjacent the walls thereof in a position to be contacted by the hot gases as they move around the walls and axially toward the outlet.
 2. A cooling chamber construction according to claim 1, wherein said solid coolant block is of L-shaped cross section and includes a leg portion forming a radially inwardly extending annular flange adjacent the outlet and providing a weir for regulating the flow of the gases.
 3. A cooling chamber construction, according to claim 1, wherein said coolant bLock includes a plurality of longitudinally extending grooves therein providing means for forming a plurality of eddies of gases adjacent the wall of said coolant.
 4. A cooling chamber construction, according to claim 1, wherein said solid coolant is located adjacent the closed end of said chamber and opposite to the outlet.
 5. A cooling chamber construction, according to claim 1, wherein said solid coolant block is arranged in the closed end of said chamber opposite to said outlet and being of a size substantially equal to the size of said outlet.
 6. A cooling device comprising a tubular member having a closed end and an opposite end with an opening forming a discharge, means for introducing high temperature gases at at least one location adjacent the closed end for whirling tangential flow around the interior of said tubular member and for axial movement in a helical flow toward said outlet, and a solid coolant block located within said tubular member adjacent the walls thereof in a position to be contacted by said gases.
 7. A cooling device, according to claim 6, wherein said solid coolant is of L-shaped cross section and includes a leg portion forming a radially inwardly extending annular flange adjacent said outlet and providing a weir for regulating the flow of the gases.
 8. A cooling device, according to claim 6, wherein said coolant includes a plurality of longitudinally extending grooves therein providing means for forming a plurality of eddies of gases adjacent the wall of said coolant.
 9. A cooling device, according to claim 6, wherein said solid coolant is located adjacent the closed end of said tubular member and opposite to the outlet.
 10. A cooling device, according to claim 6, wherein said solid coolant is arranged in the closed end of said tubular member opposite to said outlet and being of a size substantially equal to the size of said outlet.
 11. A method of treating high temperature gases in order to permit them to be used for devices requiring gases at a lower temperature comprising tangentially directing the gases into a whirling chamber and over the surface of a solid coolant so as to cause the gases to move against the coolant and to dissolve the coolant and to be cooled thereby.
 12. A method, according to claim 11, including superimposing rotatable eddies on the primary whirling gas flow.
 13. A method, according to claim 11, including utilizing secondary axially oriented return flows in the form of a toroid which are brought about by flow induced pressure difference and frictional influences in said whirling chamber for the ablation of said coolant.
 14. A method, according to claim 11, including damming the flow of gases as they are moved in an axial direction to cause them to build up centrally and permitting the gases to move through a central outlet as the damming action causes them to build up. 